I feel like this experience were currently going through called Life is a simulation, and what feels like years or decades, is actually a much shorter amount of time.
I feel like when we die, we wake up and our real life memories return to us, and that Earth is just one of the many simulations you can play and experience, and there is just a waiting list fr every simulation and every time someone is born you move up the waiting list.
But in order to participate in any simulation you have to have your mind temporarily wiped.